Hydroelectric turbines are used for generating electricity. Many turbines are being used in rivers and streams where there is fish and other wildlife. The water that flows to the turbine is diverted from the stream. This water must be screened to prevent debris and particles from entering the turbine and damaging its moving parts. Recently several state regulatory agencies have promulagated rules for the protection of fish habitats. These rules require turbine operators to provide water channels for the fish to bypass the turbine diversions.
At the present time, turbine and fish protection is accomplished by installing vertical perforated panels (or slot - type screen panels) supported by a steel frame in the water at some distance upstream from the turbine intake. A motorized brush is made to travel across the screen and sweep debris from the screen face to prevent clogging. Typically the debris is taken downstream from the screen panels by releasing water over a weir. This same weir also serves as a bypass by providing ladders for the fish to use.
There are several problems with the preexisting systems. First, power is needed to operate the brush. The diversion is typically far removed from the power supplies at the turbine. Running power lines to the brush is troublesome and expensive. Occasionally large debris such as logs or other flotsam will jam the brush. Periodic checkups of the system are needed along with maintenance, repair and servicing of the brush.
There is need for a system for protecting turbines and fish which is self-cleaning and needs minimal operator attention.